The invention relates to scroll compressors, and more particularly to controlling compressor capacity in a scroll compressor.
Scroll compressors are widely used in refrigerant compression applications. A scroll compressor typically includes two interfitting scroll members. Each scroll member has a base with a generally spiral scroll wrap extending from the base. The wraps interfit to define a plurality of compression chambers. One scroll member is a non-orbiting scroll member, which remains at a stationary position, while the other scroll member is an orbiting scroll member, which orbits relative to the non-orbiting scroll member. The relative orbiting movement causes the wrap in the orbiting scroll member to move relative to the wrap in the non-orbiting scroll member, changing the volume of the compression chambers. This changing volume compresses refrigerant trapped in the compression chambers.
Different applications often call for scroll compressors having different chamber capacities. The chamber capacities can be changed by modifying the dimensions (e.g., the height) of the scroll wraps during compressor manufacture. Each scroll compressor will still have a fixed capacity, however, because the scroll wrap dimensions cannot change once the scroll wrap is actually in the compressor. Changing the capacity of a given compressor would require exchanging a component having one scroll wrap dimension for a corresponding component having a different scroll wrap dimension. While several methods of capacity control using various complex valving schemes have been developed, it would be desirable to develop additional methods.
There is a desire for a scroll compressor structure having an adjustable capacity.
Accordingly, the present invention is directed to a scroll compressor having an adjustable compressor capacity. One or both scroll wraps in the compressor are coupled to an actuator mount that changes the distance between the bases of the scroll members. The wraps also, preferably, adjust to compensate for this movement. This adjustment can occur via springs, gas devices, hydraulic devices, or other similar adjustment structures. As a result, the compressor capacity can be adjusted at any time and does not require replacement or exchange of compressor components.